General Electric Company

Other

Leland Stanford Junior University

General Electric Company Medical Systems

Stephen G Hushek

Norbert Joseph Pelc

Mark Alexiuk

Gordon Scarth

Mehran Fallah-Rad

Michael R Figueira

Elizabeth A Kuhn

Carl S Winalski

Manoj Saranathan

An MRI system performs a calibration prescan in which NMR projections are produced using either a spiral acquisition pulse sequence (FIG. 3) or a series of pulse sequences at a corresponding series of projection angles. The signal energies of the projections are summed to produce NMR calibration data. The signal energy in a prescribed region of interest may be calculated to provide the optimal RF transmit power when using local coils.

RF power calibration for an MRI system using multiple axis projections

An MRI system performs a calibration prescan in which NMR projection signals are produced using a calibration pulse sequence. The readout gradient employed during the acquisition of each NMR projection signal is rotated during the signal sampling such that the projection angle changes during the acquisition. The center of the field of view is weighted more heavily in the calculation of the optimal RF transmit power to provide a more accurate setting when using local coils.

RF power calibration for an MRI system using local coils

MRI images are acquired as the patient moves a joint through a range of motion. The angle of joined limbs is measured during the scan, and the measured angles are attached to corresponding images for display therewith. In one embodiment the angles are measured using interleaved navigator acquisitions from which limb orientation can be determined.

Method for measuring and adding limb angle indicia to MR images

In an MRI system a scan is performed to acquire data from which multiple intersecting slice images are reconstructed. During each pulse sequence, the slices are separately and selectively excited to produce transverse magnetization, and this magnetization is collectively refocused by a single non-selective refocusing pulse which produces an echo signal for each slice image. The flip angles of the excitation pulses are chosen to eliminate saturation lines at the slice intersections.

Intersecting multislice MRI data acquistion method

A method is described for increasing the temporal resolution of MR fluoroscopy procedures. A central portion of the image requiring a higher temporal resolution is updated more frequently using less-than-complete newly acquired NMR data. A running average of the signals produced by peripheral structures is used to form the periphery of the image and to remove artifact-producing data from the less-than-complete NMR data.

Growing community of inventors

Brookfield, WI, United States of America

Stephen G Hushek